astronomy

Jan Schilt

Jan Schilt is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jan Schilt rather than just read about it. In short: Jan Schilt (3 February 1894, Gouda – 9 January 1982, Englewood, New Jersey) was a Dutch-American astronomer, inventor of the Schilt photometer. Biography Schilt was born in 1894 in the Netherlands, and educated there under Jacobus Kapteyn.

Key takeaways

Jan Schilt belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Jan Schilt to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Jan Schilt from memory before moving on to harder problems.

Reference excerpt

Jan Schilt (3 February 1894, Gouda – 9 January 1982, Englewood, New Jersey) was a Dutch-American astronomer, inventor of the Schilt photometer.

Biography Schilt was born in 1894 in the Netherlands, and educated there under Jacobus Kapteyn. After the death of Kapteyn in 1922 he finished his PhD thesis in 1924 with Pieter Johannes van Rhijn 'On a Thermo-Electric Method of Measuring Photographic Magnitudes'. This work was mainly done at Leiden Observatory where he stayed from 1922 to 1925. He emigrated to the United States in 1925, first to Mount Wilson Observatory, in 1926 to Yale University Observatory and in 1931 he was appointed associated professor at Rutherford Observatory. In 1933 he became the Chair of Columbia University's astronomy department, a position which he filled until his retirement in 1962, when he was granted the title of Rutherford Professor of Astronomy Emeritus. Schilt's astronomical work included the invention of the Schilt photometer, a device which measures the light output (apparent magnitude) of stars on photographic plates, and, indirectly, their distances. He worked on the motions of star streams in the Milky Way Galaxy, and was director of the Yale-Columbia Southern Station in Johannesburg and Canberra, as well as Director of the Rutherford Observatory at Columbia. Schilt was noted at Columbia for walking into his classes the first day after the launch of Sputnik 1 and commenting "Well, gentlemen, it is not every day we have something new in the sky to talk about", following which he devoted the entire class to proving that Sputnik had been deliberately launched into an orbit designed to make it invisible from the United States for as long as possible (six weeks). 13,500 items of his papers are contained in the Rare Book and Manuscript Library of Columbia University.

Honor Asteroid 2308 Schilt (1967 JM) was named in his honor.

Published works Barney, Ida; Schilt, Jan (1927). "Discussion of the proper motions in the equatorial Zone". Astronomical Journal. 37: 181. Bibcode:1927AJ.....37..181B. doi:10.1086/104785. Barney, Ida; Schilt, Jan (1930). "Analysis of the Yale proper motions in the zones between +50 degrees and +55 degrees and between +55 degrees and +60". Astronomical Journal. 40: 168. Bibcode:1930AJ.....40..168B. doi:10.1086/105000.

Worked examples

Example 1 — a first encounter with Jan Schilt

Start with the simplest possible case. Write down what Jan Schilt claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jan Schilt before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jan Schilt ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jan Schilt

In research: Jan Schilt appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jan Schilt in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jan Schilt is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1894 births, 1982 deaths, 20th-century American astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for Jan Schilt outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jan Schilt in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Jan Schilt means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Jan Schilt out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jan Schilt in simple terms?

Jan Schilt (3 February 1894, Gouda – 9 January 1982, Englewood, New Jersey) was a Dutch-American astronomer, inventor of the Schilt photometer. Biography Schilt was born in 1894 in the Netherlands, and educated there under Jacobus Kapteyn.

Why does Jan Schilt matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jan Schilt?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jan Schilt.